Infrared imaging devices are used in a variety of imaging applications to capture infrared (e.g., thermal) emissions from objects as infrared images. Infrared images may also suffer from noise which may appear as non-uniformities in the infrared images. Unfortunately, conventional approaches to remove such noise are often problematic.
For example, one approach to removing noise relies on an internal or external shutter that is selectively placed in front of infrared sensors of an infrared imaging device to provide a substantially uniform scene. The infrared sensors may be calibrated based on images captured of the substantially uniform scene while the shutter is positioned in front of the infrared sensors. Unfortunately, such a shutter may be prone to mechanical failure and potential non-uniformities (e.g., due to changes in temperature or other factors) which render it difficult to implement. Moreover, in applications where infrared imaging devices with small form factors may be desired, a shutter can increase the size and cost of such devices.
Another approach uses infrared images captured from an external scene as part of a noise removal process. However, if such an approach is performed indiscriminately, actual scene data may be mistaken for noise, or vice-versa, in some cases. As a result, such an approach may introduce correction terms that inadvertently increase noise in infrared images.